US 11,969,582 B2
Syringe plunger with dynamic seal
Michael Swantner, Saxonburg, PA (US); and Michael McDermott, Berlin (DE)
Assigned to BAYER HEALTHCARE LLC, Whippany, NJ (US)
Filed by Bayer Healthcare LLC, Whippany, NJ (US)
Filed on Jun. 2, 2022, as Appl. No. 17/830,604.
Application 17/830,604 is a continuation of application No. 16/471,300, granted, now 11,351,306, previously published as PCT/US2018/012284, filed on Jan. 4, 2018.
Claims priority of provisional application 62/443,302, filed on Jan. 6, 2017.
Prior Publication US 2022/0288322 A1, Sep. 15, 2022
This patent is subject to a terminal disclaimer.
Int. Cl. A61M 5/315 (2006.01); A61M 5/31 (2006.01)
CPC A61M 5/31513 (2013.01) [A61M 2005/3123 (2013.01); A61M 2207/00 (2013.01)] 19 Claims
OG exemplary drawing
 
1. A method for increasing a seal between a cylindrical sidewall of a plunger and an inner sidewall of a barrel of a syringe, the method comprising:
pressurizing a fluid within an interior volume of the syringe to an operating pressure, wherein the plunger comprises:
a support ring comprising a first conical cap;
a cover disposed over and coupled to the support ring, wherein the cover comprises a second conical cap and the cylindrical sidewall, wherein the cylindrical sidewall comprises at least one annular rib; and
an air cavity defined between the first conical cap and the second conical cap, the air cavity defining a predetermined compliance volume such that when the plunger undergoes injection pressurization, the cover deforms and flexes into the compliance volume, wherein a distal portion of the first conical cap forms an angle with a proximal portion of the second conical cap;
deforming the cover such that the angle between the distal portion of the first conical cap and the proximal portion of the second conical cap is smaller under operating pressure than when the fluid is not under operating pressure; and
deflecting the at least one annular rib in a radially outward direction against the inner sidewall of the barrel when the angle is smaller.